Embodiments of the present application relate generally to fluidic cartridges, systems, and methods for conducting biochemical reactions and, more particularly, to systems and methods in which a fluidic cartridge engages a system base to conduct designated reactions for at least one of sample preparation or analysis.
Various biochemical protocols involve performing a large number of controlled reactions on support surfaces or within designated reaction chambers. The controlled reactions may be conducted to analyze a biological sample or to prepare the biological sample for subsequent analysis. The analysis may identify or reveal properties of chemicals involved in the reactions. For example, in an array-based, cyclic sequencing assay (e.g., sequencing-by-synthesis (SBS)), a dense array of DNA features (e.g., template nucleic acids) are sequenced through iterative cycles of enzymatic manipulation. After each cycle, an image may be captured and subsequently analyzed with other images to determine a sequence of the DNA features. In another biochemical assay, an unknown analyte having a detectable label (e.g., fluorescent label) may be exposed to an array of known probes that have predetermined addresses within the array. Observing chemical reactions that occur between the probes and the unknown analyte may help identify or reveal properties of the analyte.
There has been a general demand for systems that automatically perform assays, such as those described above. More recently, there has been a demand for a system that uses pre-packaged components that may be readily added to the system to perform a designated assay. For instance, the above systems may use a large number of solutions (e.g., nucleotides, enzymes, buffers, etc.) while conducting the designated reactions. Cartridges including all or a plurality of the solutions may be shipped to an end user who may then load the cartridge into the system. Such convenience, however, is not without challenges. For instance, the interface between the cartridge and the system may develop unwanted leaks.
In addition, the above systems may include sipper tubes that extend into reservoirs of the cartridge to withdraw the corresponding solutions therefrom. Due to manufacturing tolerances, it may be difficult to position a sipper tube such that all of the solution within the reservoir can be removed. To ensure that a reservoir holds a sufficient amount of the solution for the assay, the reservoir is typically filled to have a volume that is more than necessary. Often, a residual volume (or dead volume) of the solution is not used during the assay and wasted.
Accordingly, a need exists for cartridges that reduce the residual volumes of solutions that are not used during an assay while also providing an interface that does not allow excessive leakage.